(a) Field of the Invention
The present invention relates to a method and system for measuring a vertical position and left and right positions of the head of a driver in a vehicle, using infrared lamps and infrared sensors.
(b) Description of the Related Art
Recently, a technology of recognizing the head position of a driver in a vehicle has been studied in depth, as interest improving safety and convenience of vehicles has risen. The head position of a driver is used as an important parameter in an algorithm that controls the operations of a headrest and a seat and the operation of an airbag to prevent drowsy driving or minimize damage to the driver's head and neck in an accident.
In the related art, the head position of a driver is calculated with respect to the front and rear positions of the driver seat, and accordingly, the position of the driver seat may be determined based on signals from a seat track position sensor that detects the front and rear positions of the driver seat and the head position of the driver may be determined from the determined position of the driver seat.
However, the head position of a driver may be different to determine based on the degree of inclination of the backrest and/or the position of the driver in the driver seat, even when the position of the driver seat does not change, and thus it may be difficult to precisely and accurately measure the head position of a driver.
A developed conventional method provides a headrest position adjusting device that includes a plurality of detecting electrodes disposed vertically in parallel on a seat headrest in a vehicle and detects capacitance between the head of a person in the seat and the headrest, a detection circuit that detects the vertical position of the head based on detection signals from the detecting electrodes, and a position adjusting unit that adjusts the position of the headrest based on the vertical position of the head according to the detection result from the detecting circuit, in which the position adjusting unit adjusts the position of the headrest, when the distance between the headrest and the head is the same as or less than a predetermined distance, and the position adjusting unit stops or moves the headrest to a predetermined position, when the distance between the headrest and the head is greater than the predetermined distance.
However, in the conventional method, the capacitance detecting electrode may fail, when static electricity is generated at the headrest and/or the head, and detection signals of a battery electrode may have an influence directly on the driver's head, potentially causing harm to human health. Further, this system may be unable to measure the left and right positions of the driver's head, even though it provides the detection circuit that detects the vertical position of a head based on the signals from the detection electrode and adjustment of the vertical position of the headrest, based on the vertical position of the head.
The above information disclosed in this section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.